Born: December 7, 1915
Klara grew up in Rzeszow, a Polish city with a population of approximately 30,000. The Mintzbergs were observant Jews. Klara's mother supported the family by running their fabric store. Her father was an ardent Zionist. He dreamed of immigrating to Palestine and encouraged Klara to join a Zionist youth group.
1933-39: After finishing secondary school, Klara was elected to serve on the board of directors of Poland's Ha-No'ar Ha-Ziyoni youth movement; she was the only woman on the board. She studied education and psychology at the university and worked with the educator Janusz Korczak at his orphanage in Warsaw. When war broke out in September 1939, Rzeszow was occupied by German forces. With the help of members of her youth movement, Klara fled to the Soviet-occupied sector of Poland.
1940-45: Klara married in 1940 and moved to Lvov. Klara and her husband were wanted by the Soviets because of our Zionist activities, so they went into hiding. The Germans invaded Lvov on June 30, 1941, and began killing the city's Jews that same day. In 1942 they fled to Warsaw and lived with Klara's mother and sister. They had obtained false papers and were living as Christians, but her mother secretly observed Jewish traditions. One day they found a note under the door: "The gold crosses you wear don't help. We know you're Jews." They left that night.
With the help of a relative, Klara and her family went into hiding and survived the war. In October 1945 they sailed to Palestine [the Yishuv] aboard the "Transylvania."